Astronomers have recently validated the finding of an unusual guest from outside our solar system — a newly identified interstellar comet. Officially designated 3I/ATLAS, the comet was initially observed on July 1 by NASA’s ATLAS survey telescope located in Chile.
This marks just the third recognized interstellar object to traverse our cosmic vicinity, following the trails of 1I/ʻOumuamua in 2017 and 2I/Borisov in 2019.
The interstellar comet is presently journeying towards the inner solar system from the direction of the constellation Sagittarius. It remains over 400 million miles away from the Sun but is anticipated to hit its closest point—just within Mars’s orbit—around October 30. Even at this proximity, however, it poses no danger to Earth.
What makes this object particularly thrilling is its origin. Unlike standard comets that revolve around the Sun, 3I/ATLAS originates from interstellar space. This implies it probably formed in a different star system and spent ages wandering between the stars before being temporarily captured by our Sun’s gravity. The ESA also shared details about the discovery on Bluesky before it received its official name.
Following its discovery, astronomers have compiled further “pre-discovery” images of the interstellar comet, with some tracing back to mid-June. These images were captured by several observatories, including ATLAS stations across the globe and the Zwicky Transient Facility in California. By merging past and current data, researchers are striving to refine the comet’s path and gain additional insights into its composition.
Examining an interstellar comet like this provides a unique opportunity to investigate the foundational elements of planets and stars beyond our solar system. Scientists are hurriedly collecting as much information as they can while it is still observable by ground-based telescopes. By December, 3I/ATLAS will re-emerge from behind the Sun, presenting a second opportunity for observation.
Its precise size and composition are still under investigation, but researchers are optimistic that it will yield new understandings of how other planetary systems develop and change. Although these types of visitors are uncommon, astronomers predict that our solar system may be concealing millions of similar interstellar objects deep within the Oort Cloud surrounding the solar system.
